Electrophysiological catheters of various configurations are currently available which can be guided through internal spaces, e.g., a heart chamber or a vessel of a patient undergoing surgery. Such catheters, typically have one or more electrodes associated therewith for taking electrical measurements (commonly referred to as electrograms) or performing some other application specific function within the internal spaces.
Navigation systems for conventional electrophysiological catheters which have a single navigated electrode typically determine the location of a point on the catheter which is usually close to the single navigated electrode within the internal space, or a location associated with the electrode, e.g., a location at the wall of the heart or within a heart chamber. A measurement, as desired, e.g., an electrogram, is then captured for the location, or another application specific function is performed, e.g., ablation, mapping, etc. The single electrode catheter is then moved to another location to perform additional application functions, e.g., capture another measurement. In other words, a point by point acquisition process is performed. The point by point acquisition process is time consuming and the comparable data from such an acquisition process is somewhat limited by the degree to which successive patient activities, e.g., heart cycles, are identical. For example, when heart cycles are different for successively taken cardiac measurements at multiple locations, the data captured is not actually representative of the same event and therefore, not necessarily comparable, as opposed to such cardiac measurements being taken at different locations during the same heart cycle.
To eliminate such point by point acquisition using single navigated electrode catheters, multiple electrode catheters, i.e., catheters having two or more electrodes, have been deployed. For example, one such known catheter includes a three dimensional basket at the end of the catheter including electrodes along spines of the basket for positioning within the internal space. Measurements at such electrodes when in contact with the defining structure of the internal space wherein the basket is positioned are taken. However, such catheters tend to be relatively complex, and thus costly, as compared to single electrode catheters.
Various other multiple electrode catheters tend to be less costly and more easily maneuvered than complex catheters, e.g., basket catheters. One such maneuverable multiple electrode catheter includes a single flexible elongated electrode support body with multiple electrodes distributed along the length of the support body. The catheter also has a steering mechanism for selectively bending, i.e., flexing and holding, the maneuverable portion of the catheter in a shape. In such a manner, the electrodes can be placed in contact against a structure defining the internal space into which the catheter has been inserted. Each electrode is typically operably connected for taking measurements at the electrode's particular location within the internal space.
With the positioning of such an elongated multiple electrode catheter, data can be captured and gathered from all of the electrodes simultaneously without repositioning of the catheter, vastly improving the speed and quality of data gathering. However, the difficulty with respect to such a configuration is that the location of each of the multiple electrodes must be determined, i.e., each of the electrodes must be navigated, as the maneuverable portion of the catheter has been steered into a particular shape and location. In order to provide such navigation, wiring overhead and sensor electronics overhead is substantially increased. Typically, the overhead requirements necessary for providing navigation of an electrode limits navigation for most multiple electrode catheters to no more than two or three electrodes. To navigate more than two or three electrodes is particularly cost prohibitive, as well as degrading to catheter steerability because of the increased stiffness of the catheter due to the number of required wires.
As a result, a need exists for a system and/or method for effectively and efficiently navigating multiple numbers of electrodes such that the location of such electrodes within the internal space can be used as desired, e.g., mapping, ablation, etc. The present invention provides for such navigation of multiple electrodes alleviating the problems as described above and others that will become apparent from the description below.